Modular well intervention assembly

ABSTRACT

A modular well intervention assembly includes a jack assembly having increased stroke length that can be installed directly over a well or above a BOP assembly. Modular work platforms and a telescoping mast assembly can be installed and secured in place around the jack assembly. Tongs can be suspended from a hydraulically operated “track system”, eliminating the need for a conventional tong pole and spring. Pipe can be manipulated relative to the well intervention assembly using a hydraulically powered pipe handling device.

CROSS REFERENCES TO RELATED APPLICATION

Priority of U.S. Provisional Patent Application Ser. No. 61/764,075, filed Feb. 13, 2013, incorporated herein by reference, is hereby claimed.

STATEMENTS AS TO THE RIGHTS TO THE INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

None

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a modular assembly for conducting intervention operations on oil and/or gas wells. More particularly, the present invention pertains to a modular assembly for conducting operations on wells including, without limitation, work over operations and snubbing operations.

2. Brief Description of the Prior Art

Intervention operations have been performed on oil and/or gas wells for many years. When a conventional drilling or workover rig is used to perform such operations, a well is frequently “killed” using drilling mud or other drilling fluids. In such instances, the hydrostatic pressure exerted by such drilling mud or fluids in a wellbore equals or exceeds the reservoir pressure of the well, thereby leaving the wellbore in a pressure-balanced state at the earth's surface.

In certain circumstances, it may be impractical or undesirable to kill a well (that is, to offset reservoir pressure with hydrostatic pressure in order to put the well in a pressure-balanced state) prior to performing well intervention operations. In such cases, operations are sometimes performed even though positive fluid pressure exists at the upper opening of the well. However, in order to perform such operations in a pressurized well system, specialized well intervention equipment is required.

One common type of conventional system used to conduct well intervention operations in pressurized wells is the so-called “snubbing unit”, also sometimes referred to as a hydraulic workover unit (“HWU”). Such conventional snubbing units generally comprise well servicing systems capable of running and retrieving pipe and other jointed tubular goods, including under “live” well conditions such as high pressure. Specifically, conventional snubbing units comprise hydraulic power systems and associated equipment to install such pipe and tubular goods in a well, and remove such pipe and/or tubular goods, with or without the presence of surface pressure.

Conventional snubbing units typically comprise multiple sets of pipe gripping devices, commonly referred to as “slips,” that can be operated in sequence in order to grip the external surface of pipe as it is “snubbed” into or out of a well. Although specific slip configurations can vary, conventional snubbing units typically comprise at least four separate sets of slips that can be used during well intervention operations. Certain of said slips remain stationary, while other slips are capable of moving or traveling, typically in axial alignment with the surface portion of a well being serviced.

Conventional snubbing units also typically comprise a snubbing “basket” that forms a support or work platform for personnel. In many cases, such basket also contains hydraulic controls for operating various features of a snubbing unit, as well as blow out preventer (“BOP”) and hydraulic valve controls.

Snubbing units and HWU's have sometimes suffered from negative connotations, likely resulting from the nature of the intervention operations that such units are typically called upon to perform. For example, snubbing units and HWU's are frequently used to conduct operations on wells suffering from well control problems, blowouts, stuck pipe and/or other negative or dangerous conditions. As a result, snubbing units or HWU's are often viewed as a means of last resort, thereby negatively impacting the perception of such systems. Further, such conventional snubbing units and HWU's suffer from a number of practical and operational limitations.

Thus, there is a need for a well intervention system that can be used to perform well intervention operations in a safe, efficient and effective manner. Such well intervention system should be more versatile than conventional snubbing units and HWU's, while overcoming the practical and operational limitations associated with such conventional systems.

SUMMARY OF THE INVENTION

In a preferred embodiment, the well intervention assembly of the present invention comprises a jack assembly that can be installed over a well or, in most cases, on a BOP assembly installed over the upper opening of a well. Such jack assembly has an increased stroke length relative to conventional hydraulic jack systems; whereas conventional hydraulic jack systems typically have a standard stroke length of approximately ten (10) feet, the jack assembly of the present invention beneficially has a stroke length of at least fifteen (15) feet. Said jack assembly is oriented so that the stroke orientation of said jack assembly is substantially axially aligned with the upper portion of said well.

The well intervention assembly of the present invention further comprises an expanded “work window.” A work window of a conventional snubbing unit, which is generally equivalent to the stroke or travel length of a hydraulic jack assembly, ends at or near the top of said stroke length. By contrast, the well intervention assembly of the present invention comprises a hydraulic jack assembly that permits easy access to said work window. As a result, hydraulic cylinders of the jack assembly of the present invention can optimize space occupied by such work window which is typically dormant or unused on conventional snubbing units.

The well intervention assembly of the present invention further comprises a plurality of modular work platforms that can be installed and secured in place around said jack assembly. In a preferred embodiment, nuts, bolts or other similar fasteners are not required to secure such work platforms in place around said jack assembly; instead, said modular platforms are secured in place using guided hooks and pins.

The modular work platforms of the present invention are beneficially designed for ease of transportation. For example, said work platforms can be conveniently and efficiently transported to and from offshore or other remote locations using vessels, trucks or other means. When installed, said platforms provide a stable, secure and safe work environment for personnel, while stairs and ladders provide means for personnel to move or traverse between such work platforms. Importantly, such platforms eliminate the need for personnel to be suspended in the air using harnesses or other similar mechanisms.

Hydraulic tongs are secured on a hydraulically operated “track system”, eliminating the need for a conventional tong pole and spring. The design of the present invention allows a tong operator ease of use in positioning tongs within the intervention assembly of the present invention, including over the center of a well. Further, the movement of pipe (including over the center of said well) is also automated by means of a hydraulically powered pipe handling arm, thereby eliminating most, if not all, hand-to-iron contact and greatly improving personnel safety.

BRIEF DESCRIPTION OF DRAWINGS/FIGURES

The foregoing summary, as well as any detailed description of the preferred embodiments, is better understood when read in conjunction with the drawings and figures contained herein. For the purpose of illustrating the invention, the drawings and figures show certain preferred embodiments. It is understood, however, that the invention is not limited to the specific methods and devices disclosed in such drawings or figures.

FIG. 1 depicts a perspective view of a jack assembly of the modular well intervention assembly of the present invention, installed on the upper end of a conventional BOP assembly.

FIG. 2 depicts a perspective view of a jack assembly and a plurality of lower modular deck assemblies installed along one side of said jack assembly.

FIG. 3 depicts a perspective view of a jack assembly and a plurality of lower modular deck assemblies installed along two sides of said jack assembly.

FIG. 4 depicts a perspective view of a rotary table installed on said jack assembly of the present invention.

FIG. 5 depicts a perspective view of a mid-deck assembly installed above said lower deck assemblies of the present invention.

FIG. 6 depicts a perspective view of an upper deck assembly installed above said mid-deck assembly of the present invention.

FIG. 7 depicts a side view of the components depicted in FIG. 6, as well as a telescoping mast assembly of the present invention in a substantially retracted position.

FIG. 8 depicts a perspective view of the modular intervention assembly of the present invention, with said telescoping mast assembly in a substantially extended position.

FIG. 9 depicts a detailed perspective view of the highlighted area depicted in FIG. 8.

FIG. 10 depicts a front view of the modular intervention assembly of the present invention, with said telescoping mast assembly in a substantially extended position.

FIG. 11 depicts a detailed view of the highlighted area depicted in FIG. 10.

FIG. 12 depicts a front view of the modular intervention assembly of the present invention, with said telescoping mast assembly in a substantially extended position.

FIG. 13 depicts a detailed view of the highlighted area depicted in FIG. 12.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 depicts a perspective view of a jack assembly 10 of the modular well intervention assembly of the present invention installed on an upper end of a conventional BOP assembly 100, which is itself disposed on the upper opening of a well that extends into the earth's crust. It is to be observed that modular well intervention assembly of the present invention, in general, and jack assembly 10, in particular, can be installed on any number of different well configurations. As such, the depiction of modular well intervention assembly of the present invention installed on BOP assembly 100 is illustrative only, and is not intended to be, and should not be construed as, limiting in any way. As depicted in FIG. 1, BOP assembly 100 comprises a plurality of ram assemblies 101, as well as a top flange (not depicted in FIG. 1) disposed at the upper extent of said BOP assembly 100.

Still referring to FIG. 1, jack assembly 10 of the present invention comprises substantially planar lower base plate 1, substantially planar middle plate 2 and substantially planar upper plate 3. Said lower plate 1, middle plate 2 and upper plate 3 are oriented substantially parallel to each other in a substantially stacked relationship. Lower base plate 1 has central bore 5 extending through said lower base plate, while middle plate 2 has central bore 6 extending through said middle plate and upper plate 3 has upper bore 7 extending through said upper plate. Said bores 5, 6 and 7 are at least partially aligned with one another.

In a preferred embodiment, lower base plate 1 has lower flange member 4. Said lower flange member 4 can be used to connect jack assembly 10 to the upper end of BOP assembly 100. Although other connection means can be utilized without departing from the scope of the invention, said lower flange member 4 can be bolted to an upper connection flange of said BOP assembly 100 in a manner that is well known.

Jack assembly 10 further comprises a plurality of hydraulic cylinders 11. In a preferred embodiment, said jack assembly 10 comprises four (4) hydraulic cylinders 11 oriented in a substantially square pattern. Said hydraulic cylinders 11 further comprise hydraulic cylinder piston rods 12 that can be extended from barrels of said hydraulic cylinders 11. Upper plate member 3 is connected to said cylinder piston rods 12, such that extension of said cylinder piston rods 12 from hydraulic cylinders 11 will cause said upper plate 3 to travel upward relative to BOP assembly 100.

Still referring to FIG. 1, rotary table mounting brackets 8 are disposed on upper plate member 3, while hook-like deck connection brackets 13 are disposed along at least two (2) opposing sides of said plate member 3. Lower mast connection brackets 17 are disposed on lower plate member 1, while upper mast connection brackets 18 are disposed on upper plate member 3. Lower deck connection brackets 19 are disposed on lower plate member 1.

FIG. 2 depicts a perspective view of jack assembly 10 mounted on BOP assembly 100, while lower modular deck assembly 20 and lower modular deck assembly 30 are attached to one side of said jack assembly 10. Although other configurations can be employed without departing from the scope of the present invention, said lower modular deck assemblies 20 and 30 are similar in construction and operation.

Lower modular deck assembly 20 comprises a plurality of individual structural support members 21 that are joined to form a support frame, typically oriented in a substantially square or rectangular external shape and defining an inner space. Individual support members 21 can be of tubular steel construction or other material in order to provide desired strength characteristics while also being relatively lightweight. Lower modular deck assembly 20 further comprises floor surface 22 and stair case 23 leading from said floor surface 22 to the upper extent of said lower modular deck assembly 20. Optional door 24 is hingedly attached to lower modular deck assembly 20 and can be closed to block external access to a portion of jack assembly 10.

Similarly, lower modular deck assembly 30 also comprises a plurality of individual structural support members 31 that are joined to form a support frame defining an inner space. Like modular deck assembly 20, individual structural support members 31 are typically oriented in a substantially square or rectangular external shape and have the same basic construction as structural support members 21. Lower modular deck assembly 30 further comprises floor surface 32 and stair case 33 leading from said floor surface 32 to the upper portion of said lower modular deck assembly 30. Floor surface 32 can include opening 32A which is aligned with the upper end of stair case 23 of lower modular deck assembly 20. Optional door 34 is hingedly attached to lower modular deck assembly 30 and can be closed to block external access to a portion of jack assembly 10.

Still referring to FIG. 2, stair case 110 can provide access to lower modular deck assembly 20, typically from supporting structure, such as a deck of a platform or drilling structure. Said stair case 110 can lead to landing member 111 attached to said lower modular deck assembly 20. Said landing member 111 can be constructed from individual structural support members 112, as well as floor 113 and hingedly attached access door 114 which, when closed, can block access to an internal portion of lower modular deck assembly 20 (as well as the remainder of the modular well intervention assembly of the present invention).

FIG. 3 depicts a perspective view of jack assembly 10 with lower modular deck assemblies 20 and 30 installed along one side of said jack assembly 10, and lower modular deck assemblies 40 and 50 installed on the opposite side of said jack assembly 10. It is to be observed that lower modular deck assemblies 40 and 50 are similar in construction and configuration as lower modular deck assemblies 20 and 30.

Specifically, lower modular deck assembly 40 comprises a plurality of individual structural support members 41 that are joined to form a support frame, typically oriented in a substantially square or rectangular external shape and defining an inner space. Individual support members 41 can be of tubular steel construction or other material in order to provide desired strength characteristics while also being relatively lightweight. Lower modular deck assembly 40 further comprises floor surface 42 and ladder 43 (as opposed to a stair case) leading from said floor surface 42 to the upper extent of said lower modular deck assembly 40. Optional door 44 is hingedly attached to lower modular deck assembly 40 and can be closed to block external access to a portion of jack assembly 10.

Lower modular deck assembly 50 also comprises a plurality of individual structural support members 51 that are joined to form a support frame defining an interior space. Like modular deck assemblies 20, 30 and 40, individual structural support members 51 are typically oriented in a substantially square or rectangular external shape. Lower modular deck assembly 50 further comprises floor surface 52 and ladder 53 leading from said floor 52 to the upper portion of said lower modular deck assembly 50. Floor surface 52 can include opening 52A which is aligned with the upper end of ladder 43 of lower modular deck assembly 40. Optional door 54 is hingedly attached to lower modular deck assembly 50 and can be closed to block external access to a portion of jack assembly 10.

Lower modular deck assemblies 20, 30, 40 and 50 each comprise work platforms for personnel and/or equipment that can be installed and secured in place around jack assembly 10; said work platforms can be used by personnel to perform operations around jack assembly 10. In a preferred embodiment, no nuts, bolts or other similar fasteners are required to secure such deck assemblies in place around said jack assembly; instead, said modular platforms are secured in place using guided hooks and pins. Although not visible in FIG. 4, lower modular deck assemblies 20 and 40 are connected to jack assembly 10 using lower deck connection brackets 19 on jack assembly lower plate 1 (depicted FIG. 1). Similarly, lower modular deck assemblies 30 and 50 are connected to jack assembly 10 using deck connection brackets 13 disposed along sides of upper plate 3 of jack assembly 10 (depicted in FIG. 1).

FIG. 4 depicts a perspective view of modular well intervention assembly of the present invention with rotary table assembly 15 installed on upper plate 3 jack assembly 10. Said rotary table assembly 15 has central bore 16, and can be secured in place on upper plate 3 using rotary table mounts 8 (which are best visible in FIG. 1). Central bore 16 of rotary table assembly 15 is beneficially axially aligned with central bore 5 that extends through lower base plate 1, central bore 6 that extends through middle plate 2 and upper bore 7 that extends through upper plate 3. Rotary table assembly 15 provides a support structure for mounting of pipe slips which can be used to grip the external surface of a section of pipe disposed through central bore 16, while rotary table assembly 15 can also apply torque to such a pipe section in order to rotate said pipe.

FIG. 5 depicts a perspective view of mid-deck assembly 60 installed immediately above lower deck assemblies 30 and 50. Although other configurations can be employed, in a preferred embodiment mid-deck assembly 60 comprises a plurality of individual structural support members 61 that are joined to form a support frame defining an interior space. Individual support members 61 can constructed of tubular steel or other material in order to provide desired strength characteristics while also being relatively lightweight. Optional panels 62 can be provided along the sides of mid-deck assembly.

Although not shown in FIG. 5, mid-deck assembly 50 can also comprise a support floor, as well as at least one integrated stair case and/or ladder within the interior space thereof. The floor of said mid-deck assembly includes at least one opening to permit passage to and from lower deck assembly 30 and/or lower deck assembly 50. Said floor also includes an opening, generally aligned with jack assembly 10; when extended, the traveling portion of said jack assembly 10 (including, without limitation, upper plate member 3) can pass though said mid-deck assembly 50 when jack assembly 10 is extended. Said mid-deck assembly 50 can house hydraulic valves and connections associated with the operation of modular well intervention assembly of the present invention.

FIG. 6 depicts a perspective view of an upper deck assembly 70 installed above said mid-deck assembly. Although other configurations can be employed, in a preferred embodiment upper deck assembly 70 comprises a plurality of individual structural support members 71 that are joined to form a support frame defining an interior space. Individual support members 71 can constructed of tubular steel or other material in order to provide desired strength characteristics while also being relatively lightweight. Optional panels 72 can be provided along a portion of certain sides of upper deck assembly 70.

Upper deck assembly 70 also comprises support floor 72 that includes at least one opening to permit passage to and from mid-deck assembly 60. Said floor also includes an opening, generally aligned with jack assembly 10; when extended, the traveling portion of said jack assembly 10 (including, without limitation, upper plate member 3) can pass though said opening in upper deck assembly 70. Additionally, said upper work deck assembly 70 also includes v-door 73. Although it can have different embodiments or configurations, in a preferred embodiment said v-door 73 comprises an opening or pathway from the exterior of upper work deck assembly 70 into the interior work space defined by said upper work deck assembly 70. More specifically, said v-door 73 should permit a relatively unobstructed path from the exterior of said upper work deck assembly 70 to jack assembly 10 (as well as the area axially above BOP assembly 100 and a well situated therebelow).

In a preferred embodiment, modular work decks 20, 30, 40, 50, 60 and 70 of the present invention are beneficially designed for ease of transportation. Said work decks can be conveniently and efficiently transported to and from offshore installations and/or other remote locations using vessels, trucks or other means. When installed, said decks provide a stable, secure and safe work environment for personnel, as well as a support structure for storage or staging of materials. Steps and ladders provide means for personnel to move or traverse between such interconnected or adjoining work platforms. Importantly, such platforms eliminate the need for personnel to be suspended in the air using harnesses or other similar means while the modular well intervention assembly is being installed and removed, and while operations are being performed.

FIG. 7 depicts a side view of the components depicted in FIG. 6, as well as mast assembly 120. Mast assembly 120 can be quickly and securely attached to jack assembly 10, typically on the rear or back side of said jack assembly 10 between laterally disposed lower deck assemblies and at the approximate mid-point of mid-deck assembly 60 and upper work deck 70. Said mast assembly 120 can quickly, efficiently and securely attach to jack assembly 10 using connection pins and brackets. Referring to FIG. 1, said mast assembly 120 (not depicted in FIG. 1) can connect to jack assembly 10 using lower mast connection brackets 17 on jack lower plate 1, as well as upper mast connection brackets 18 disposed on jack upper plate 3.

Mast assembly 120 (also sometimes referred to as a “gin pole”) comprises a plurality of hydraulically powered telescoping members that can be selectively extended or retracted in order to adjust the length of said mast assembly 120. Further, said mast assembly 120 is equipped with a plurality of winch assemblies; in a preferred embodiment, said mast assembly 120 has a main winch 123 (typically positioned at or near the upper end of said mast assembly 120) that can be used to lift large or heavy tools and assemblies, as well as at least one smaller winch 124 that can be used to lift pipe sections or relatively lightweight tools or assemblies. As depicted in FIG. 7, mast assembly 120 is equipped with two opposing counterbalance winches 124 that can be used to quickly and efficiently lift pipe and other relatively light materials on said modular well intervention assembly including, without limitation, upper work deck 70.

Still referring to FIG. 7, the modular well intervention assembly of the present invention can also include a rear landing deck 130. Said rear landing deck 130 can extend in cantilever relationship from the rear side of jack assembly 10, lower deck assemblies 20 or 30, or some combination thereof. Said rear landing deck assembly 130 can be used to provide improved access to the base of mast assembly 120, as well as for addition storage facilities.

FIG. 8 depicts a perspective view of the modular well intervention assembly of the present invention, with telescoping mast assembly 120 extended, while FIG. 9 depicts a detailed perspective view of the highlighted area depicted in FIG. 8. Referring to FIG. 8, mast assembly 120 comprises lower telescoping mast member 121 and upper telescoping mast member 122 that can be selectively extended or retracted to adjust the length of said mast assembly 120. Mast assembly 120 is equipped with main winch 123 disposed at the upper end of said upper telescoping mast member 122. Two opposing counterbalance winches 124 are beneficially positioned at or near the upper end of lower telescoping mast member 121.

As depicted in FIG. 8, a winch 124 can be used to quickly and efficiently lift a pipe section 200 from below the modular well intervention assembly of the present invention (such as, for example, from a pipe rack located on a deck near the base of BOP assembly 100) and position said pipe section 200 in proximity to upper work deck 70.

FIG. 9 depicts a detailed view of the area highlighted in FIG. 8. As depicted in FIG. 9, upper work deck assembly 70 is equipped with pipe handling assembly 90. Said pipe handling assembly 90 comprises body section 91 and opposing pipe receiving members 92 having rollers 93. Said opposing pipe receiving members 92 form a yoke-like recess for receiving pipe section 200. Said body section 91 of pipe handling assembly 90 is slideably and pivotally disposed on elongate track 94. In a preferred embodiment, said elongate track 94 extends from a position at or near the forward facing opening of v-door 73 to a position at or near the rear of upper work deck assembly 70.

Still referring to FIG. 9, as pipe section 200 is lifted upward by winch 124 toward upper work deck assembly 70 and suspended by mast assembly 120, body section 91 of pipe handling assembly 90 can be positioned at or near the front of elongate track 94 in proximity to v-door 73. In this position, opposing pipe receiving members 92 form a yoke or cradle for receiving the lower portion of said pipe section 200. When desired, body section 91 can be moved along elongate track 94 in a direction away from v-door 73, thereby positioning pipe section 200 in axial alignment over bore 16 of rotary table assembly 15 (and a well positioned therebelow). The movement of pipe section 200 (including over the center of such well) using pipe handling assembly 90 eliminates virtually all hand-to-iron contact by personnel which greatly improves safety and reduces risk of injury.

FIG. 10 depicts a front view of the modular intervention assembly of the present invention, with telescoping mast assembly 120 extended, while FIG. 11 depicts a detailed view of the highlighted area depicted in FIG. 10. Pipe section 200 is lifted upward by winch 124 toward upper work deck assembly 70 and suspended by mast assembly 120. Pipe section 200 can be advantageously positioned in axial alignment over bore 16 of rotary table assembly 15 using pipe handling assembly 90.

Power tong unit 83, which is suspended from tong positioning assembly 80, can be used to apply torque to pipe section 200 in order to rotate said pipe, particularly when said pipe section 200 is disposed over rotary table assembly 15. In a preferred embodiment, tong positioning assembly 80 generally comprises support beam 81 and hydraulically-powered telescoping member 82. Said support beam 81 and telescoping member 82 are mounted at or near the top of upper work deck 70, and are oriented in substantially perpendicular alignment to elongate track 94 of pipe handling assembly 90. Power tong unit 83 is suspended from telescoping member 82 using tong mounting line 84.

When not in use, power tong unit 83 can be moved away from the area above rotary table assembly 15 by retracting telescoping member 82 of tong positioning assembly 80. In such retracted position, power tong unit 83 is located away from v-door 73 and the area above rotary table assembly 15, so as to avoid interference with any ongoing operations in such vicinity. Power tong unit 83 can be selectively moved into position above rotary table assembly 15 using telescoping member 82 of tong positioning assembly 80. Additionally, body section 91 of pipe handling assembly 90 can be pivotally raised to provide clearance in the area above jack assembly 10.

FIG. 12 depicts a front view of the modular intervention assembly of the present invention, with said telescoping mast assembly 120 extended, while FIG. 13 depicts a detailed view of the highlighted area depicted in FIG. 12. As depicted in FIGS. 12 and 13, jack assembly 10 is extended. Telescoping member 82 of tong positioning assembly 80 is retracted to move power tong unit 83 away from the area above extended jack assembly 10 and rotary table assembly 15. Further, body section 91 of pipe handling assembly 90 is pivotally raised to provide additional clearance in the area above jack assembly 10.

Unlike conventional snubbing units and/or HWU's, it is to be observed that the well intervention assembly of the present invention can be easily and efficiently installed and removed including, without limitation, on platforms or other installations lacking crane boom length and/or lifting capacity. The well intervention assembly of the present invention is exceptionally versatile, allowing for the various components other than jack assembly 10 to be installed in virtually any sequence or order.

In operation, jack assembly 10 can be installed over a well or, in most cases, on a BOP assembly (such as BOP assembly 100) which is itself installed over the upper opening of a well. In a preferred embodiment, jack assembly 10 of the present invention has an increased stroke length relative to conventional hydraulic jack systems; whereas conventional hydraulic jack systems have a standard stroke length of approximately ten (10) feet, jack assembly 10 of the present invention beneficially has a stroke length of at least fifteen (15) feet or more.

Unlike conventional snubbing units, the well intervention assembly of the present invention comprises an expanded work window. As a result, hydraulic cylinders 11 of jack assembly 10 of the present invention extend through space occupied by such work window (which is typically dormant or unused on conventional snubbing units). Further, the work deck assemblies of the present invention, individually and collectively, provide a stable, secure and safe work environment for personnel, while also providing access to such work window. Steps and ladders provide means for personnel to move or traverse between such work deck assemblies; personnel are not required to be suspended in the air using harnesses or other similar mechanisms.

During well intervention operations, pipe can be retrieved from a well using the well intervention assembly of the present invention. In one common illustrative example, the upper portion of a pipe string can be externally gripped using a set of slips attached to rotary table assembly 15 disposed on upper plate 3 of jack assembly 10. As said jack assembly 10 is hydraulically extended, said gripped pipe can be pulled upward and out of said well (and any BOP assembly installed above said well). As said jack assembly is hydraulically extended, telescoping member 82 of tong positioning assembly 80 can be retracted to move power tong unit 83 away from the area above extended jack assembly 10 and rotary table assembly 15. Additionally, body section 91 of pipe handling assembly 90 can be pivotally raised to provide clearance in the area above jack assembly 10.

Once said pipe section has been pulled a desired distance out of said well, lower pipe gripping slips can be set against the external surface of said pipe string at lower plate 1 of jack assembly 10 in order to suspend such pipe. Thereafter, telescoping member 82 of tong positioning assembly 80 can be extended to move power tong unit 83 into proximity with such pipe. Said power tong unit 83 can be used to apply torque to such pipe and unscrew a threaded pipe connection. Thereafter, a disconnected or unscrewed length of pipe can be attached to a line connected to winch 124 of mast assembly 120. Pipe handling assembly 90 can be used to move said pipe section toward v-door 73 of upper work deck 70, and said pipe section can be lowered for further handling to a pipe rack or other staging area below using winch 124. Thereafter, the process can be repeated to remove additional lengths of pipe from said well. The well intervention assembly of the present invention can also be beneficially used to install pipe sections into a well bore.

The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention. 

What is claimed:
 1. A well intervention assembly comprising: a) a jack assembly mounted above a well; b) at least one modular deck assembly attached to said jack assembly; c) a mast assembly attached to said jack assembly; and d) at least one winch mounted to said mast assembly.
 2. The well intervention assembly of claim 1, wherein said jack assembly further comprises: a) a plurality of plate members oriented substantially parallel to each other; and b) at least one hydraulic cylinder disposed between said plurality of plate members.
 3. The well intervention assembly of claim 2, wherein each of said plurality of plate members has a bore extending through said plate members and said bores are at least partially aligned with each other.
 4. The well intervention assembly of claim 1, wherein said mast assembly further comprises: a) a first elongate member; b) a second elongate member telescopically disposed within said first elongate member; and c) at least one hydraulic cylinder adapted to selectively extend and retract said second elongate member relative to said first elongate member.
 5. The well intervention assembly of claim 1, wherein said at least one modular deck assembly comprises: a) a structural support frame defining an interior space; and b) a floor.
 6. A well intervention assembly comprising: a) a jack assembly mounted above a well, wherein said jack assembly further comprises: i) a plurality of plate members oriented substantially parallel to each other, wherein each of said plate members has a bore extending through said plate member and said bores are at least partially aligned with each other; and ii) at least one hydraulic cylinder disposed between said plurality of plate members; b) at least one modular deck assembly attached to said jack assembly; c) a telescoping mast assembly attached to said jack assembly; d) at least one winch mounted to said mast assembly; and e) a rotary table disposed on said jack assembly.
 7. The well intervention assembly of claim 6, wherein said mast assembly further comprises: a) a first elongate member; b) a second elongate member telescopically disposed within said first elongate member; and c) at least one hydraulic cylinder adapted to selectively extend and retract said second elongate member relative to said first elongate member.
 8. The well intervention assembly of claim 6, wherein said at least one modular deck assembly comprises: a) a structural support frame; and b) a floor.
 9. The well intervention assembly of claim 6, wherein said at least one modular deck assembly comprises: a) a plurality of lower deck assemblies; b) a mid-deck assembly disposed over said lower deck assemblies; and c) an upper deck assembly disposed over said mid-deck assembly.
 10. The well intervention assembly of claim 9, wherein said upper deck further comprises a v-door.
 11. The well intervention assembly of claim 10, further comprising a pipe handling assembly adapted to guide a section pipe suspended from said mast assembly between said v-door and said jack assembly.
 12. The well intervention assembly of claim 10, further comprising a tong support assembly adapted to selectively position a tong unit over said rotary table.
 13. The well intervention assembly of claim 12, wherein said tong support assembly further comprises: a) a telescoping beam member; and b) a line extending between said telescoping beam member and said tong unit.
 14. A well intervention assembly comprising: a) a jack assembly mounted above a well, wherein said jack assembly further comprises: i) a lower plate member having a bore extending through said lower plate member; ii) a middle plate member having a bore extending through said middle plate member, wherein said middle plate member is oriented substantially parallel to said lower plate member and the bores or said lower and middle plate members are at least partially aligned; iii) at least one hydraulic cylinder disposed between said lower and middle plate members; iv) an upper plate member having a bore extending through said upper plate member, wherein said upper plate member is oriented substantially parallel to said lower and middle plate members and the bores or said upper, lower and middle plate members are at least partially aligned; v) at least one hydraulic cylinder disposed between said upper and middle plate members; b) at least one modular deck assembly attached to said jack assembly; c) a telescoping mast assembly attached to said jack assembly comprising: i) a first elongate member; ii) a second elongate member telescopically disposed within said first elongate member; and iii) at least one hydraulic cylinder adapted to selectively extend and retract said second elongate member relative to said first elongate member; d) at least one winch mounted to said mast assembly; and e) a rotary table disposed on said jack assembly.
 15. The well intervention assembly of claim 14, wherein said at least one modular deck assembly comprises: a) a plurality of lower deck assemblies; b) a mid-deck assembly disposed over said lower deck assemblies; and c) an upper deck assembly disposed over said mid-deck assembly.
 16. The well intervention assembly of claim 15, wherein said upper deck further comprises a v-door.
 17. The well intervention assembly of claim 16, further comprising a pipe handling assembly adapted to guide a section pipe suspended from said mast assembly between said v-door and said jack assembly.
 18. The well intervention assembly of claim 16, further comprising a tong support assembly adapted to selectively position a tong unit over said rotary table.
 19. The well intervention assembly of claim 18, wherein said tong support assembly further comprises: a) a telescoping beam member; and b) a line extending between said telescoping beam member and said tong unit. 